5 point coil mystery

[steve ravet]

I looked up the coil that is on my '91 Caprice TBI 350 external coil HEI.  It has 5 connectors, 4 regular wires plus the high tension one to the distributor.  This one may work for ION, although the
coil itself isn't all that small.  It has two pink wires, and two white wires.  The large pink one is +12 from the ignition switch.  The small pink one is connected to the large one inside the coil,
and runs power from the coil over to the EST module.  One white one is the switched ground from the EST module to the primary, that fires the coil.  The other white one is... a mystery!  The schematic
shows that the second white wire is connected to the first inside the coil, but doesn't show a wire from the connector to the harness (although there is one).  I suppose it's a tach signal or
something.  This motor lives in my S-10 Blazer, and I remember having a mystery white wire that went to the bulkhead connector, but wasn't documented in the manual.  I left it hanging...

What's this have to do with anything?  The secondary of the coil is grounded thru the body of the coil.  Not real useful, but still separated from the primary.  You could mount the coil on an
insulated stand, and put ION stuff between it and ground.

--steve


--
Steve Ravet
steve at imes.com
International Meta Systems
www.imes.com